Set Up

• Go to https://github.com and make sure you are logged in
• Open RStudio

Agenda

1. Why Git and GitHub?
2. Traditional Workflow vs. Git Workflow
3. Make a repository on GitHub
4. Make local changes in RStudio
5. Make remote changes on GitHub
6. Pull it all together!

Key Questions

• How do you organize files?
• Do you keep different versions of files as your work progresses?
• Could you find your files in 5 years?
• Could you open them?
• Do you backup your files?

Insert quote here !

Why Git and GitHub?

• Git: version control system
  • Manages the evolution of a set of files- called a repository
  • A repository is a top-level directory that has Git version control enabled
  • Think of it like an amped up “Track Changes”
  • Data scientists use for managing data, figures, reports, and source code
• GitHub: the hosting service for Git-based projects
  • Think of an amped up “DropBox”
  • Publicity and shareability
  • Collaboration

The Typical Workflow vs. Git Workflow

• “Why the heck did I save all of these?”

• Commits are snapshots that are saved at particular points in time

• Commit messages require you to annotate your changes

Git Workflow

Git Workflow

Git Workflow

Let’s Try!

Make a repo on GitHub

• Go to https://github.com and make sure you are logged in
• Click green “New Repository” button
• Fill this in:
  • Repository name: volcanoRepo (whatever you want!)
  • Description: “This volcano repo contains some great volcano info” (some text is good for the README)
  • Public
  • YES - Initialize this repository with a README
• Accept defaults for everything else
• Click green “Create Repository” button
• Copy the HTTPS clone URL via the green “Clone or Download” button

Clone the new GitHub repo to your computer via RStudio

• In RStudio, start a new Project:
  • File > New Project > Version Control > Git.
  • In “Repository URL”, paste the URL of your new GitHub repo.
  • Accept default project directory name
  • Pay attention to where Project will be saved
  • Click “Create Project”

• Should now be in a new local RStudio Project that represents what we just created on GitHub including the README.md file

• Take a look around. Compare RStudio files and GitHub repo.

Let’s make some local changes!

• From RStudio, modify the README.md file by adding a line of text.
  • i.e. “Seven volcanoes have permanent lava lakes”.
• Save!
• Commit these changes to your local repo from the terminal. How?
• In the Rstudio Terminal:

# git add -A
# git commit -a -m "[commit message]"
  ##The commit message is your own annotation
  ##For example "Edited readme to include volcano info"
# git push origin master

• Go back to your browser and refresh
• We should see our new text included in the README.
• Click "Commits" to see your commit message history.
• Cool, huh?

Let’s make some local changes in another way!

• From RStudio, make a new modification to the README.md file by adding a new line of text.
  • i.e. These volcanoes include Erta Ale, Ambrym, Mount Yasur, Mount Erebus, Kilauea, Nyiragongo, and Masaya.
• Save!
• Commit these changes to your local repo from the Git panel. How?
  • Click the “Git” tab in the upper right pane
  • Check “Staged” box for any files whose modifications you want to commit
  • Click “Commit”
  • Type your commit message
  • Click “Commit” again
• Push local changes to GitHub
  • Click green “Push” button to send local changes to GitHub
• Refresh browser and confirm local changes propagated

Let’s make remote changes from GitHub!

• From your browser, click on the README.md file
• Click on the pencil for “edit this file”
• Add a new line of text to this file
  • i.e. Mauna Loa is the largest volcano on Earth.
• Edit the commit message
• Click the green "Commit Changes" button
• Back to RStudio
  • Check out your README.md
  • Click the blue "Pull" button
  • Check out the README.md again

Testing R Markdown

Contributors & References

• Chris Prener, PhD, Professor of Sociology, Saint Louis University
  • https://github.com/chris-prener
• https://happygitwithr.com
• https://education.github.com/

Appendix A: Set Up

• Register an account with GitHub
  • https://github.com
• Install/update RStudio
• Install Git
  • https://git-scm.com/downloads
• Introduce yourself to Git

# install if needed (only do this once)
# install.packages ("usethis")

#library(usethis)
#use_git_config(user.name = "Jane Doe", user.email= "jane@example.org")